Rhodiola Rosea for Coronary Microvascular Disease

Inclusion Criteria: 1. Repeated chest pain attacks with typical exertional angina pectoris or resting angina pectoris attacks; 2. Coronary normal or stenosis \< 20%; 3. Ischemic depression in ST segment during resting or exercise; 4. Blood flow reserve (CFR) of the anterior descending coronary artery \< 2.0; 5. Subjects or their guardians agreed to participate in this study. Exclusion Criteria: 1. Previous myocardial infarction or PCI or CABG treatment; 2. A history of heart failure or LVEF \< 50%; 3. Severe arrhythmia; 4. Myocarditis, Pericardium Disease, Valvular Disease, or Cardiomyopathy; 5. A history of stroke within half a year; 6. Diabetes difficult to control; 7. Refractory hypertension or hypertension accompanied by left ventricular wall thickness \> 12 mm; 8. Familial hypercholesterolemia; 9. Takayasu arteritis, Kawasaki disease or coronary artery malformation; 10. Pregnant or nursing, or having the intention to give birth within one year; 11. Hepatic or renal dysfunction; 12. Other diseases which may cause serious risks to patients; 13. Requiring warfarin anticoagulant therapy; Taking potassium channel opener, CCB, ACEI drugs or traditional Chinese medicines; 14. Allergic to contrast agents or blood products; 15. Patients who participated in clinical research of other drugs within 3 months before being selected.